a. The Field of the Invention
This invention relates to the field of three dimensional computer modeling. In particular, the invention describes an process to build and display a three dimensional model of physical objects from a two dimensional image of the physical objects.
b. Background Information
Many computer programs are now available to create three-dimensional models. However, making the process of creating a three-dimensional model simple and easy to accomplish with helpful feedback has become a challenging task. In some previous systems, a user, using a standard Computer Aided Design (CAD) program, can create a model from measurements of the physical objects and physical space. For example, 3D models are created by measuring the dimensions of physical objects and entering the shape, size, and relative position of the physical object in the model by the appropriately calculated coefficients of the object's geometric formula. Almost any geometric shape can be entered in such a format. Entering this information and displaying it to the user in a manner that allows easy review, feedback and modification has not been adequately addressed by prior art systems.
Some prior art systems create a three-dimensional model from an input file created by the user. A user writes the mathematical formula for the geometric shapes in a list format. A specific format must be followed. The program then reads the input file, creates the primitives in the order they are listed and displays them to the user. During the creation of the list of objects, the user has no visual feedback as to the size or location of an object. This lack of visual feedback makes creating the model difficult for the user.
Other systems have provided dialog boxes or preset formats for entering the coefficients of geometrical shapes. For example, in the AutoCAD.TM. CAD program by clicking on a tool icon, a dialog box displays the parameters that must be entered to create a certain geometric primitive. The user then enters the required coefficients to create the primitive. The user relies on the program to enter the data in the correct format. Then, the individual primitive can be displayed immediately to the user. However, there is no feedback displaying the discrepancies between the 3D model and the actual arrangement of physical objects being modeled nor conflicts between individual primitives.
In other systems the computer displays the primitives and indicates locations where primitives conflict. For example, the program will show where two solid objects overlap in the 3D model. However, this is all information about elements of the model relative to other elements of the model itself. There is no feedback of how the model's appearance compares or conflicts with the actual appearance of the objects to the viewer or to an image of the objects.
Therefore, what is needed is a method and apparatus that allows a user to easily create a 3D model that looks like the physical objects and space and provides feedback of discrepancies between the model and an actual image of the objects.